Peripheral Arterial Disease

Question 1

Why does peripheral artery disease occur?

Answer 1

Atherosclerosis causing stenosis of arteries

Question 2

What are risk factors for PAD?

Answer 2

Non-Modifiable: FHx, age, male

Modifable: DM, hypertension, obesity, smoking, hyperlipidaemia

Question 3

What is the chief feature of PAD?

Answer 3

Intermittent claudication: cramping pain in calf, thigh or buttock after walking for a given distance (the claudication distance) and relieved by rest limping

Question 4

What are symptoms in PAD?

Answer 4

Cramping pain in calf, thigh, buttock after walking for a given distance (claudication distance), relieved by rest.
Ulceration, gangere and footpain at rest
Burning pain at night relieved by hanging legs over side of bed.

Question 5

Describe claudication? What does calf claudication suggest? Buttock claudication?

Answer 5

Cramping pain in calf, thigh, buttock after walking for a given distance (claudication distance), relieved by rest.

Calf claudication suggests femoral artery disease
Buttock claudication suggests iliac artery disease

Question 6

What are the cardinal features of critical ischaemia?

Answer 6

Ulceration
Gangrene
Foot pain at rest - burning pain at night relieved by hanging legs over side of bed

Question 7

What is Leriche’s syndrome?

Answer 7

Buttock clausidcation ± impotence
Absent femoral pulse
Pale cold leg

Due to aorto-iliac occlusive disease e.g. saddle embolus at aortic bifurcation

Question 8

What is Buerger’s disease?

Answer 8

Non-atherosclerotic smoking related inflammation and thrombosis of veins and middle sized arteries causing thrombophlebitis and ischaemia –> ulcers and gangrene

Thromboangitis obliterans

Question 9

What is the classification for PAD?

Answer 9

1 Asymptomatic
2 Intermittent claudication
3 ISchaemic rest pain
4 Ulceration/gangrene (critical ischaemia)

Question 10

What are the signs for PAD?

Answer 10

Absent femoral/popliteal/foot pulses
Cold/white leg
Atrophic skin
Punched out ulcers
Postural dependent colour change
Buerger’s angle - angle that leg gets pale wen raised off the couch - of <20 degrees
Cap reflill of > 15 seconds in severe ischaemia

Question 11

What is Buerger’s sign?

Answer 11

Raise leg off couch - angle that leg gets pale - positive if < 20

Buerger’s test involves lying the patient supine and raising their legs until they go pale and then lowering them until the colour returns (or even becoming hyperaemic). The angle at which limb goes pale is termed Buerger’s angle; an angle of less than 20 degrees indicates severe ischaemia.

Question 12

What tests for PAD?

Answer 12

Bloods:
HbA1c - exclude DM
Arteritis - ESR/CRP
FBC (anaemia/polycythaemia)
U&E (renal disease)
Lipids (dyslipidaemia)

Bedside:
ECG (cardiac ischaemia)

Special: 
Thrombophilia screen
Ankle-brachial pressure index (ABPI) 
Normal 1-1.2 
PAD = 0.5-0.9
Critical limb ischaemia < 0.5 or ankle systolic <50mmHg

Question 13

What is ABPI?

Answer 13

Ankle-brachial pressure index (ABPI)
Normal 1-1.2
PAD = 0.5-0.9
Critical limb ischaemia < 0.5 or ankle systolic <50mmHg

Any ABPI value >1.2 should be interpreted with caution, as calcification and hardening of the arteries may cause a falsely high ABPI.
Note: false results from incompressible calcified vessels in severe atherosclerosis e.g DM

Question 14

What imaging can be done for PAD?

Answer 14

Colour duplex US

MR./CT angiography for extent and location of stenoses

Question 15

what advice would you give to PAD patient?

Answer 15

Quite smoking
Lose weight
Treat HTN
Treat cholesterol
Control DM
Take antiplatelet - clopidogrel

Question 16

How is claudication managed?

Answer 16

Supervised exercise programmes - reduces symptoms by improving collateral blood flow (2h per week for 3 months)
Encourage patient to exercise to the point of maximal pain.

Vasoactive drugs: in those who do not want revascularisation and exercise fails

Question 17

What surgical interventions can be used in PAD?

Indications for this?

Answer 17

Percutaneous transluminal angioplasty - balloon inflated in narrowest segment - stented

Surgical reconstruction - bypass graft e.g. femoral-popliteal bypass

Amputation - relieve intractable pain and death from sepsis/gangrene - knee preserved where possible - gabapentin for phantom limb pain

Exercises for claudication have not helped
Risk factor modification has been discussed.

Question 18

What are symptoms/signs of acute limb ischaemia? Investigation?

Answer 18

6 Ps
Pale
Pulseless
Painful
Paralysed
Paraesthesia
Perishingly cold

Mottling of skin

Acute limb ischaemia is often characterised by a sudden onset of these symptoms. A normal, pulsatile contralateral limb is a sensitive sign of an embolic occlusion.

Routine bloods, including a serum lactate (to assess the level of ischaemia), a thrombophilia screen (if <50yrs without known risk factors), and a group and save, should be taken, along with an ECG.

Suspected cases should be initially investigated with beside Doppler ultrasound scan (both limbs), followed by considering a CT angiography

Question 19

What i management for acute limb ischaemia?

Answer 19

Emergency - revascularisation within 4-6h to save limb
Oper surgery or angioplasty
If occlusion is embolic - surgical embolectomy or local thombolysis

Anticoagulate with heparin after procedures and look for source of emboli

Be aware of post-op reperfusion injury and compartment syndrome

If the cause is embolic, the options are:

Embolectomy via a Fogarty catheter
Local intra-arterial thrombolysis*
Bypass surgery (if there is insufficient flow back)

If the cause is due to thrombotic disease, the options are:

Local intra-arterial thrombolysis
Angioplasty (Fig. 3)
Bypass surgery
Irreversible limb ischaemia (mottled non-blanching appearance with hard woody muscles) requires urgent amputation or taking a palliative approach.

Question 20

What causes acute limb ischaemia?

Answer 20

Thrombosis in situ whereby an atheroma plaque in the artery ruptures and a thrombus forms on the plaque’s cap

Emboli whereby a thrombus from a proximal source travels distally to occlude the artery
The original thrombus source may be as a result of AF, post-MI mural-thrombus, abdominal aortic aneurysm, or prosthetic heart valves

Graft/angioplasty occlusion

Trauma - compartment syndrome